The field of this invention includes methods and equipment for measuring fabricated plate structures. Sheet metal and other structural plate products are conventionally cut to size and shape. Apertures in the plate are punched or otherwise created. Such processing proceeds according to predetermined design considerations. Quality control requires that the finished plates be remeasured to confirm the accuracy of their length, width, precise location of the apertures, and squareness.
Heretofore, it has been a practice in such quality control operations to utilize a table surface with a straight gauge means as a reference for measurements. Electronic measuring devices have been associated with the reference and a digital display to measure the length of plates.
Reissue patent U.S. Pat. No. Re. No. 34,078 brought an improvement to the art of measuring plates with a selectively retractable pin in the slot of a measuring table. This improvement made the measuring table a more powerful, convenient tool for determining plate length in an industrial quality control operation. However, some types of dimensional conformities are still difficult to verify on a measuring table. For instance, squareness and perpendicularity of plate edges are difficult to verify on conventional measuring tables.
Therefore, it is a principal object of this invention to provide a method and means for measuring the squareness of plate edges on a measuring table.
It is a further object of this invention to provide a measuring table attachment for measuring squareness which can squarely traverse the length of the table relative to a straight reference gauge with minimal interference with measuring activity above the table and clearance about the table.
It is a further object of this invention to provide a gauge generating a digital signal indicative of squareness capable of being processed by the gauge itself or an existing digital readout on the table.
It is a further object of this invention to provide a mounting and conveying structure which protects the gauge so mounted and conveyed from damage due to collisions.
It is a further object of this invention to provide a measuring device which minimizes the number of measurements required on the measuring table to verify squareness.
It is further an object of this invention to provide additional functions on a measuring table so squareness can be measured, the handling of plates is reduced, and off-table measurements are avoided.
These and other objects will be apparent to those skilled in the art.